Method of manufacturing a bearing

ABSTRACT

A method of manufacturing a bearing includes, firstly, injecting a mixture of metal powder into a mold to form a semi-finished product. Then the semi-finished product is sintered. After that, the sintered semi-finished product is fine machined, and then washed, to form the bearing.

BACKGROUND

1. Technical Field

The disclosure relates to methods of manufacturing bearings, and particularly to a method of manufacturing a bearing used in equipment such as spindle motors found in various electronic devices.

2. Description of the Related Art

At present, bearings are widely used in spindle motors, with the spindle motors applied in devices such as compact disc (CD) drives, digital video disc (DVD) drives, hard disk drives, laser beam printers, floppy disk drives and heat-dissipation fans. Spindle motors require bearings with a small size, a high rotational accuracy, and a long working lifetime. The bearing defines a bearing hole therein, and a shaft is received in the bearing hole.

A typical method for manufacturing such kind of bearing includes the processes of: (1) manufacturing a semi-finished product with a bearing hole therein; and (2) performing a chemical etching or an electrolysis electric discharge process on the semi-finished product. However, the small size of the bearing results in difficulties in manufacturing the bearing with high precision. This generally makes manufacturing of the bearing both time-consuming and expensive. The above-described method is not very suitable for mass-production of the bearing with high precision.

Therefore, it is desirable to provide a method of manufacturing a bearing suitable for mass-production with high precision.

BRIEF DESCRIPTION OF THE DRAWINGS

The components of the structural drawing are not necessarily drawn to scale, the emphasis instead being placed upon clearly illustrating the principles of the structure associated with the present method.

FIG. 1 is a schematic, cross-sectional view of a fan, the fan incorporating a bearing made according to an embodiment of a method of the present disclosure.

FIG. 2 is a flow chart of an exemplary method employed in manufacturing the bearing of FIG. 1.

DETAILED DESCRIPTION

Referring to FIG. 1, a fan 20 includes a bearing 40 made in accordance with an embodiment of a method of the disclosure. The bearing 40 is used for fixing a shaft 10 on an impeller 30 of the fan 20. The impeller 30 includes a hub 32, and a plurality of blades 34 extending radially and outwardly from an outer periphery of the hub 32. The hub 32 includes a circular top wall 320, and a cylindrical sidewall 322 extending downwardly from an outer periphery of the top wall 320. A fixing hole 323 is defined in a center of the top wall 320. An annular buckle portion 324 protrudes inwardly from an inner circumferential face of the top wall 320 which surrounds the fixing hole 323.

The bearing 40 is cylindrical. An annular buckle groove 42 is defined in an outer periphery of the bearing 40. The bearing 40 extends through the fixing hole 323 of the hub 32. The buckle portion 324 of the hub 32 is buckled in the buckle groove 42 of the bearing 40. The bearing 40 defines an axial hole 43, which extends through both a top end and a bottom end thereof. The shaft 10 extends through the axial hole 43 and is fixed in the bearing 40.

Referring to FIG. 2, a method of manufacturing the bearing 40 comprises the following steps:

step 101: providing a hollow mold (not shown), and injecting metal powder (such as, a mixture of copper powder and iron powder) into the mold to form a semi-finished product. Alternatively, the semi-finished product can be formed by pressure molding.

step 102: placing the semi-finished product into a mesh belt furnace (not shown) to sinter the semi-finished product.

step 103: fine machining the sintered semi-finished product, and then washing the sintered semi-finished product. The sintered semi-finished product can be fine machined in a sealed molding chamber using a shaping machine.

step 104: immersing the semi-finished product into antirust oil in a vacuum condition (preferably, under a vacuum degree of from 0˜5 mm Hg (millimeters mercury)).

step 105: performing a deoiling process on the semi-finished product to separate the antirust oil from the semi-finished product, thereby forming the bearing 40.

The above-described method for manufacturing the bearing 40 is suitable for mass-production, with the bearings 40 having high precision.

It is to be further understood that even though numerous characteristics and advantages have been set forth in the foregoing description of embodiments, together with details of the structures and functions of the product(s) associated with the embodiments, the disclosure is illustrative only; and that changes may be made in detail, especially in the matters of shape, size, and arrangement of parts within the principles of the disclosure to the full extent indicated by the broad general meaning of the terms in which the appended claims are expressed. 

What is claimed is:
 1. A method of manufacturing a bearing, the method comprising: injecting a mixture of metal powder into a mold to form a semi-finished product; sintering the semi-finished product; and fine machining and washing the sintered semi-finished product to form the bearing.
 2. The method of claim 1, wherein forming the semi-finished product comprises pressure molding.
 3. The method of claim 1, wherein the semi-finished product is sintered in a mesh belt furnace.
 4. The method of claim 1, wherein the sintered semi-finished product is fine machined in a sealed molding chamber using a shaping machine.
 5. The method of claim 1, further comprising immersing the washed semi-finished product into oil in vacuum condition; and performing a deoiling process on the semi-finished product to separate the oil from the semi-finished product.
 6. The method of claim 5, wherein the oil is antirust oil.
 7. The method of claim 5, wherein a vacuum degree of the vacuum condition is in a range of from 0 millimeters mercury (mm Hg) to 5 mm Hg.
 8. The method of claim 1, wherein the mixture of metal powder is a mixture of copper powder and iron powder.
 9. The method of claim 1, wherein the formed bearing is configured for fixing a shaft on an impeller of a fan. 